• Korean Journal of Crystallography
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• v.11 no.4
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• pp.224-230
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• 2000

We have been investigated the flaking mechanism of the soda-line glass. The pH of aqueous solution approached to 10 and increased with reaction time by ion exchange reaction between Na/sup +/ ion of glass and H/sup +/ ion of aqueous solution under the conditions of below pH 9 of start solution. The relationship between the pH of solution and reaction time shows logarithm. Total dissolution reaction of glass components by OH/sup -/ ion in aqueous seems to be dominant after the pH solution reached to 10 and the dissolution rate linearly increased with reaction time. The above tow reactions are simultaneously occurred. The dissolved Ca/sup 2+/ ions are reprecipitated on the glass surface to Ca-compound. The flakes are formed by the separation of leached layer of glass due to the different thermal expansion coefficient.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.09a
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• pp.165-180
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• 2004

Phosphor contents are critical to the interfacial reaction and IMC behavior. - If content is too low, the dissolution rate will be very fast. - If content is too much, the cracks during interfacial reaction and the IMCs spalling will easily occur. The spalling of IMCs caused the brittle fracture of solder joint under shear test. IMCs from chemical reaction influences to the mechanical properties and life time. Composition changes from chemical reaction influence to the life time.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.243-245
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• 2013

Rate equations are exactly solved for the reversible consecutive reaction of the first-order and the time-dependence of concentrations is analytically determined for species in the reaction. With the assumption of pseudo first-order reaction, the calculation applies and determines the concentration of product accurately and explicitly as a function of time in the unimolecular decomposition of Lindemann and in the enzyme catalysis of Michaelis-Menten whose rate laws have been approximated in terms of reactant concentrations by the steady-state approximation.

• KSBB Journal
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• v.15 no.4
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• pp.402-404
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• 2000

This work is method that uses a hydrolysis for increasing yield of paclitaxel in plant cell cultures. The best pH is 3.0 to obtain a maximum yield at fixed reaction temperature and time t pH 3.0 reaction temperature 80$^{\circ}C$ and reaction time 8 hr give the highest yield which is three time of control. This is very simple and efficient method to increase paclitaxel yield in plant cell cultures.

• Journal of the Ergonomics Society of Korea
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• v.11 no.2
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• pp.47-56
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• 1992

In this paper, a mathematical model of learning curve is proposed to study the fi- nger's reaction time. The model is a logarithmic linear type which represents a lear- ning curve appropriately, and parameters are estimated by the linear. The learning coefficient and percentage of a reaction time can easily computed in the mathematical model. This quantitative approach provieds an important information to be used fot the working capqbility qualification of re-employment as well as the adaptability estimation of aged workers.

• Proceedings of the ESK Conference
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• 1992.10a
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• pp.113-120
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• 1992

In this paper, a mathematical model of learning curve is proposed to study the finger's reaction time. The model is a logarithmic linear type which represents a learning curve appropriately, and parameters are estimated by the linear. The learning coefficient and percentage of a reaction time can be easily computed in the mathematical model. This quantitative approach provides an important information to be used for the working capability qualification for re-employment as well as for the adaptability estimation of aged workers.

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.907-912
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• 2009

Complex breakup behavior in the revival wave has been observed in the Belousov-Zhabotinsky(BZ) reaction system containing 1,4-cyclohexanedione (1,4-CHD) in the dish divided into two compartments with a sliding window. A same reaction mixture is poured into the two compartments individually with time difference. Wave propagation exhibited different behavior in the revival wave of the reaction system. This was largely dependent on the progress time prior to the pouring into each compartment and on the gap between the times of pouring into the two compartments. The revival wave in the reaction system is induced spontaneously as a new wave train with a long time lag after the disappearance of the initially induced wave. A thoroughgoing study of the chaotic breakup of propagating chemical wave train was to be possible since the revival wave has a longer wavelength, clearer wave-train patterns, and longer duration period.

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.5
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• pp.840-851
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• 2021

In this study, we used a chemiluminescence reaction to investigate the removal effect of pet soil, such as dog blood, urine and feces. The soiled fabrics were washed with a standard laundry course of 30℃ and a washing time of 30 min and a pet care laundry course of 40-60℃ and a washing time of 100 min. The detergency was evaluated by the surface reflectance and chemiluminescence reaction (bloodstain detection by luminol test and urine-stain and feces-stain detection by UV blacklight test) before and after washing. The surface reflectance results did not show any difference in detergency for both courses, whereas the chemiluminescence reaction did. The detergency of the pet care course compared to the standard course was 101% according to the surface reflectance and 120% according to the chemiluminescence reaction. Therefore, residual stains not detected by surface reflectance can be evaluated through chemiluminescence reaction, and it was confirmed that pet stains can be managed more hygienically by washing for a long time at a high temperature.

• PNF and Movement
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• v.9 no.1
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• pp.31-38
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• 2011

Purpose : Sit-to-stand (STS) is one of the important activities of daily living (ADL) and each of its parameters is used frequently. This study aimed to examine the influence of different seat height on performance time and floor reaction force strength during an STS movement. Methods : Fifteen young-adult male subjects participated in this study. The subjects were divided into three groups based on lower leg length. Subjects performed an STS movement twice from chairs at height adjusted by the lower leg length of each subject. To examine the influence of the chair seat height, ground reaction forces during a STS performed with 3 chair heights adjusted to each subjects lower leg length were compared. Results : Vertical ground reaction force and time during an STS movement were measured to evaluate. Parameters regarding ground reaction force were selected for analyses. Significant differences were found in ground reaction force at G1 was greater than G2 and G3. Conclusion : The STS movement achievement strategy differed since chair seat height changes relatively by the difference in lower leg length. When conducting the ability to achieve STS movement rating test, chair seat height considering each subject's lower leg length may be needed.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1578-1583
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• 2003

Time-Optimal solutions for attitude control with reaction wheels as well as with thrusters are studied. The suggested varying-time-sharing ratio thrusting is found to reduce the maneuvering time enormously. The hybrid control such as sequential hybrid and simultaneous hybrid with reaction wheels and thrusters are considered. The results show that simultaneous hybrid method reduces the maneuver time very much. Spacecraft model is KOrea Multi-Purpose SATellite(KOMPSAT)-II, which is being developed by KARI in KOREA as an agile maneuvering satellite.